IMHO the original camo over the rear part of the fuselage was over-sprayed with a darker tone (RLM 74 Dunkelgrau - the greenish colour) and then over-sprayed again with dense "squiggles" in a lighter grey tone as seen on many Bulgarian Bf-109G. The latter is usually described as "Light Bulgarian Grey" and is not RLM 76 but a more neutral light grey colour.
Compare 3 photos of the same a/c - the top one is from late September 1944, the bottom 2 are from the early summer of the same year:
One can see that the top photo does not show the "squiggles" - a sign that the a/c was re-painted again during the application of the white identification markings (in Sept. 1944).
And here is Stoyanov under the nose of an unidentified G-6, described as "his plane". This could be the Green 1 (compare e.g. areas in RLM 74 and 75 around the "beule" or the darker area behind and over the exhausts with the same areas visible on the photo above). Anyway, no guaranties here, just speculations.
Most of the existing colour profiles for this plane (Green 1) do not show the real mottling of the rear fuselage.
Attached are 2 photos from the same unit 382-nd Yato (Staffel), 3/6 Orlyak (Group) - Green 6 with a very well pronounced "squiggles" with hard contours on a dark background. It is not impossible that the Green 1 and 6 have been painted by the same hand. The "squiggles" normally start around the cockpit area.
The pilot in the flight suit is Stoyanov, the officer with the hat, Manolev.
The original camo scheme could be (with a great probability) the Regensburg-scheme with the dark area in front and around the cockpit incl. the canopy. The latter has a very light rear fuselage which has been actually heavily over-sprayed later:
Cheers!